MicroRNA-520c-3p suppresses vascular endothelium dysfunction by targeting RELA and regulating the AKT and NF-κB signaling pathways.

Endothelial injury, which can cause endothelial inflammation and dysfunction, is an important mechanism for the development of atherosclerotic plaque. This study aims to investigate the functional role of miR-520c-3p in vascular endothelium during inflammatory diseases such as atherosclerosis. Quantitative real-time PCR was used to detect miR-520c-3p expression in in human umbilical vein endothelial cells (HUVECs) after treatment with platelet-derived growth factor (PDGF). Furthermore, the effects of miR-520c-3p overexpression and silencing on cell proliferation, adhesion, and apoptosis were assessed. Bioinformatics analysis and Biotin-labeled miRNA pull-down assay were used to confirm the targets of miR-520-3p. Then, the effects of miR-520c-3p on AKT and NF-κB signaling pathways were detected by western blot. Herein, we observed that the expression level of miR-520c-3p was downregulated in HUVECs under PDGF stimulation. Overexpression of miR-520c-3p not only decreased cell adhesion but also promoted proliferation and inhibited apoptosis to protect the viability of endothelial cells. It was confirmed that RELA is the target of miR-520c-3p. MiR-520c-3p inhibited the protein phosphorylation of AKT and RELA, and si-RELA reversed the promotion of AKT and RELA protein phosphorylation by anti-miR-520c-3p. In summary, our study suggested that miRNA-520c-3p targeting RELA through AKT and NF-κB signaling pathways regulated the proliferation, apoptosis, and adhesion of vascular endothelial cells. We conclude that miR-520c-3p may play an important role in the suppression of endothelial injury, which could serve as a biomarker and therapeutic target for atherosclerosis.